Voltage-responsive relay



Nov. 1, 1949 H. E. SCHLEICHER 2,486,337

VOLTAGE-RESPONSIVE RELAY Filed Nov. 2, 1944 3 Sheets-Sheet 1 46 9 0 70 five/1Z0 1 .2. 90 HAROLD E.SCHLEICHER 1 fy/lzs aitarne s MMM Nov. 1, 1949 H. E. SCHLEICHER 2,486,887

VOLTAGE-RESPONSIVE RELAY Filed Nov. 2, 1944 3 Sheets-Sheet 2 i .5. M 92 T 1.

HAROLD E.SCHLE|CHER Qykzl? aTY-orueys Nov. 1, 1949 Filed Nov. 2, 1944 H.E.$CHLECHER VOLTAGE-RESPONSIVE RELAY' 3 Shets-$heet 3 .Zhveniar- 7d HAROLD E, SCHLEICHER Patented Nov. 1, 1949 VOLTAGE -RESPONSIVE RELAY Harold E. Schlei'cher, West Hartford, Conn., as-

signor to The Arrow-Hart & Hegeman Electric Company, Connecticut Hartford, Conn., a corporation of Application November 2, 1944, Serial No. 561,600 16 Claims. (01. 200-877 This invention relates to a voltage-responsive switch operable by electromagnetic action and useful as a relay to control the operation of circuit breakers or other electric devices on the occurrence of predetermined under-voltage or overvoltage conditions.

Among the objects of the invention are: One, the provision of a dynamically balanced mechanism whose parts are all practically immune to shock, in the sense that their closed circuit or open circuit condition will not be even momentarily changed on occurrence of vibrations and shocks of great magnitude;

Two, the provision of a balanced rotary switch mechanism operated by a balanced rotary electromagnetic operating means;

Three, the provision for double throw, in a mechanism possessing the foregoing characteristics, enabling use for under-voltage and overvoltage operation;

Four, the provision in a mechanism possessing the foregoing characteristics, of over-center action of the movable contacts, incorporating means to insure positive snap motion of the contacts at the moment of separation to avoid zero pressure or dead spot conditions at the instant of separation;

Five, the provision in a mechanism possessing the foregoing characteristics, of adjustment of the so-called drop-out and pick-up conditions by means of adjustment of stationary contacts which controls spring action components that participate in the contact opening movement;

Six, the provision, in a switch of the foregoing type, for renewal of stationary contact surfaces by reversal of the contacts;

Seven, the provision, in a switch possessing the foregoing characteristics, of adjustment of the armature position, to compensate for coil characteristic variations.

Other objects and advantages will become apparent to those skilled in the art as the invention is described in connection with the drawings.

In the drawings:

Fig. 1 is an assembled plan view of the invention;

Figs. 2, 3, 4 and 5 are transverse section views along lines 2-2, 3-3, 4-4 and 5-5 respectively of Fig. 1;

Fig. 6 is a detailed view showing in plan the movable contact mounting structure in association with the fixed contacts;

Fig. 7 is a sectional view of the structure shown in Fig. 6 with the section being taken along lines l1 of Fig. 6;

Fig. 8 is a detailed view partly in section of the fixed contact and its mounting structure;

Fig. 9 is a detailed view partly broken away of I the electro magnet armature and associated structure;

Fig. 10 is a detail section view with the section taken along line l0-|0 of Fig. 8. A

The preferred embodiment of the invention herein described may conveniently be mounted in a cylindrical base 10 of molded insulation for assembly as a section or unit of a rotary-type electromagnetic switch station, the design, arrangement and combination of parts of this invention having been created with that possibility in mind. Nevertheless, the invention is not limited in that respect and its principles are adaptable, as will be understood by those skilled in the art, to embodiment in many forms for various conditions wherein voltage-responsive devices are employed.

The electromagnetic actuating means For causing movement of the contacts in response to variations in appliedvoltage, an elec tromagnetic device is provided comprising a U shaped core of magnetic material composed of side arms 14, i6 and an end section l8 therebetween. The arms l4, l6 and end section are each built up from laminations. A top plate or bar 20 is secured on the end section and extends over the end portions of the side arms, being secured thereto by screw bolts 22 which pass through the arms into the base so as to secure the assembled core to the base. A solenoid coil 24 is mounted on the end section l8 and is removable on removal of the screw bolts and end section I 8 without disturbing the remainder of the structure.

At the opposite end of the core, on the top and bottom thereof, non-magnetic bridge bars 25, 28 of U-shape, with out-turned ends, join the arms l4, l6 and afford mountings for armature bearings. The ends of the bridge bars are secured to the core arms I4, l6 by hollow rivets 21 through which pass screw bolts 29 which assist in securing the core on the insulating base. Between these bars 26, 28 and the ends of the core arms l4, i6 is located the rotary armature 30 made up of laminations 30a riveted between top and bottom plate bars 30b, 30c.

Armature 30 is mounted on a threaded pivot 32, being locked thereto by a lock nut 34. The pivot passes transversely through the center of the armature 30, so that the latter is dynamically balanced, thus affording in normal intended operation a minimum resistance to pivoting and maximum resistance to movement when the whole device is subjected to an unusual shock or vibration. The bearings tor the pivot 32 are mounted in the bars 26, 28. The upper bearin is a pin 36 threaded nto the center of the bar 28 and afiixed in adjusted a lock nut 38. A conically pointed end on the bearing pin fits into a conical bearing hole in the upper end of the armature pivot 32. The lower end of the pivot 32, which is conically pointed, fits into a conical recess in a bearin member seated in the lower bar 28.

For normally biasing the armature, a spring 42 is coiled about the lower end of the armature pivot 32. To anchor one end, a lug 28a is struck up from one edge of the bar 28 at its central portion. The other end of the spring 42 engages one (48) of the two lugs 48, 48 struck down from the surface of an operating disc 58 mounted on the pivot 32 for rotation therewith, and urges that lug into engagement with lug 28a. The disc 50 is located below the armature 38 and is possessed of a key hole opening 52a by means of which the disc 50 can be engaged with a reduced neck on the lower end of pivot 32, the neck having parallel fiat faces fitting into the slotted end of the key hole opening.

For operating the switch mechanism (to be presently described), an over-center, coiled tension spring 88 is afiixed at one end through a hole 62 in the surface of the disc 58 at a point diametrically opposite the spring anchor lugs 46, 48. The other end of the spring 88 is aflixed to a pin 64 upstanding from an insulating disc 66 of the switch contact mechanism.

The contact structure The switch contact structure comprises a pair of fixed contacts 10, 88 which are individually engageable by contact pins or points 88a, 9%, respectively, of a movable contact member. Disengagement of one fixed contact 18 by one movable contact point We results in engagement the other fixed contact 80 by the other movable contact point 90b. The fixed contact structures are alike. Each is supported by an inwardly extending, conductive terminal bar 12, 82, lying fiatwise in angularly-spaced positions, on the peripheral surface of the insulating base l8, and having an end extending outside with a terminal screw for wiring connections. The inner end of each terminal support has a screw-threaded aperture receiving a hollow metallic bushing 13 externally threaded for half its length. The location of the bushing relative to the terminal supports is thus adjustable and the position of adjustment is maintained by a lock nut I4.

Extending through the bushing is an axle-bolt 15, whose lower tip, extending beyond the bushing, is threaded into a contact element 16 in such position that the element is dynamically balanced so as to practically eliminate tendency to turn if the device be subjected-to shock or vibration. A look nut secures the contact element in proper angularly adjusted position on the bolt.

For the purpose of limiting pivotal movement of the contact elements, a pin 11 is mounted on each contact element in position to move between the sides or a radial slot I8 cut in the periphery of a flange 18 formed on the unthreaded lower end of the bushing 13.

To bias the contact elements, a spring II is coiled about the unthreaded portion or the bushing I3 above the flange I3, with one end pressing against the pin H. The opposite end or the spring is up-turned to engage in one or another position thereby by a of a series of peripheral notches 8 la in an anchor member 8| in the formof an internally threaded metal washer that is screwed down tight against the end or the thread on the bushing 13.

It will be apparent that the described fixed contact structure enables properly located securement of the bushings in the terminal supports and necessary angular adjustment of the contact elements within the bushing, together with variable tensioning of the bias of the contact elements. All parts are conductive to carry current from the terminal to the tips 18, 88. These tips may be channel-shaped members of preferred contact material fastened on the ends of the contact elements in position to have fiat graces engaged by the movable contact pins 98a,

b. To ensure proper balance of the fixed contact assembly counter-weights 18w may be employed when needed.

The movable contact structure comprises the previously mentioned insulating disc 66 which is pivotally mounted on a pivot pin 81 supported in a fabricated support. The support comprises a sheet metal terminal plate 58 secured upon the periphery of the insulating base between the terminal supports 12, 82 and having an end extending outside the casing with terminal screws for wire connections. The inner end has afiixed thereon a bracket 69 stamped from sheet metal into U-shape with parallel arms 69a, 69b bent up at right angles from opposite edges or one leg 690 of the U-portion thereof. Lugs on the ends of said arms extend through apertures in the terminal and are peened over to make the bracket integral with the terminal plate.

For supporting the dis-c 66, pivot bearings are mounted in the legs of the U-portion of the supporting bracket 69, one bearing being screwthreaded into the bracket for adjustment.

The movable contact carrying disc 88 has the two contact pins 98a, 90b projecting from its face at an'gularly spaced points and joined electrically by a V-shape metal strip 92. To provide good electrical connection between the V-bridge and the bracket, a pig-tail lead 84 is or may be soldered to a terminal lug 92a bent from the strip and is soldered or otherwise connected to the bracket 88.

The structure described enables two sorts of adjustment to be made whereby the device may be set for maximum sensitivity and best conditions of operation at the selected voltage condition.

(a) Adjustment of the armature to the most favorable angle for actuation (i. e. pick up) when the electromagnet becomes energized to the selected voltage is accomplished by rotating the armature 88 on its spindle 32 and looking it in adjusted position by lock nut 34. The at res or deenergized position of the spindle 32 and disc 58 which is fixedly mounted thereon remains constant because the action and location biasing spring 42 and fixed and movable stops 28a and 48 are unchanged and fixed.

(b) Adjustment so the mechanism will be actuated (i. e. pick up) or will become deenergized (i. e. drop out) at desired voltage values, is accomplished by the adjustment of the fixed contacts. Assume the parts in the position shown in Figs. 1 and 6. If the fixed contact 10 is then adjusted in a clockwise direction, movable contact 98a will be moved counterclockwise carrying the end or the spring 68 that is fastened to amass? pin I on contact-carrying disc I counterclockwise nearer the line of action of the spring I, as defined by the other end spring '0 and the axis of contact-carrying disc 0. Hence less movement is required or the armature 30 and its disc lit to carry the spring across the line of action or over-center. Adjustment of the contact Hi in a counterclockwise direction will, of course, have the opposite efl'ect and require greater movement of the armature to carry the spring over-center.

A converse condition will exist when the magnet is to be in energized position and the contact 80 is adjusted for selected drop-out voltages.

It may be observed that the optimum condition of angular adjustment of the armature to compensate for coil characteristic variations is not disturbed by the adjustment of the mechanism for selected pick up and drop-out voltages, and vice versa. The novel means for both adjustments accomplishes in a simple, accurate and practical manner the important objectives of two-way adjustment for diflerent voltages and independent armature adjustment coverin wide variations in actuating coil characteristics,

Operation From the -foregoing, it may be observed that with the parts assembled as shown in Figures '1 and 2, the armature 30 will be biased to cause engagement of the contact pin 90a with the fixed contact and disengagement oi the contacts 90b and 80. In one circuit arrangement employing the device as a voltage-responsive relay, the contacts 90a and 10 or tub and 80 may be conventionally connected in series with the devices or element in the circuit to be controlled. The relay coil 24 may be connected across the power lines of the circuit in which over or under voltage fluctuation is to be protected against. For overvoltage protection, the armature will be energized but will be adjusted to be normally under-attracted at full voltage, the contacts 10 and 900 will remain engaged. On occurrence of an overvoltage condition, the armature will be actuated counterclockwise thus carrying the over-center spring so across the line of action between the axis of the contact-carrying disc 66 and the spring anchor pin 64 on that disc, causing pivotal movement of that disc and movement of contact pin 5011 from contact 10. The armature attraction is in opposition to and overcomes the normal bias of armature biasing spring 42', neutralizing or cancelling out its action. (It has no direct effect on the separating of the contacts 10 and 90a.) Two opposed forces act on contacts 10 and 90a while they are engaged: One, the force of the contact biasing spring H; and the other, the counter-acting component of the over-center spring 60. As the latter approaches dead-center, said component decreases until it is overpowered by spring H which thereupon starts both contacts moving (while still engaged) in counterclockwise direction (Fig. 6). Thus, if the over-center spring 60 is slow moving as it reaches the deadcenter position, any tendency of the movable contact to teeter or hesitate, concomitantly creating a period of low or zero pressure between the contacts, is avoided by the positive biasing action of the stationary contactmoving within limited range-to start the movable contact on its way. As a result, pressure is maintained between the contacts up to the instant of their separation; and the movable contact is moving in contact opening direction at that instant. whereby a quick sharp break is obtained.

When the device is used for under-voltage protection, contacts 10 and "a will be normally open because the armature will be adjusted to be normally actuated at full voltage; but on undervoltages they will close by action of the overcenter spring 60 as the armature moves in response to its clockwise bias. Contacts and "b can be used to cut in and out resistances, for example.

By reversing the contact tips of the stationary contacts, the contacting surfaces can be renewed.

It will now be apparent that I have provided a sensitive relay, adapted to over-voltage or undervoltage action, possessing characteristics of positive contact separation under all conditions, having dynamically balanced movable parts. so that its operation is shockproof and vibration-proof and withal adjustable to variable conditions and flexible in use.

Many modifications within the scope of the invention will be apparent to those skilled in the art. I do not limit the invention to the specific embodiment illustrated.

I claim:

1. In a switch, electro-magnetic actuating means, a fixed contact, 'a movable contact member and an over-center spring forming the sole operating connection between said actuating means and said movable contact member to cause movement of thecontact member in direct response to operation of said electro-magnetic actuating means, means to adjust the relative positions of said contacts so as to influence the action of said over-center spring, said electro magnet comprising a pivotally balanced armature, a fieldpiece and a coil on said fieldpiece, means to remove part of said fleldpiece and said coil independently of and without varying the setting of said contacts or adjusting means.

2. In a relay switch, electro-magnetic operating means having a field piece and a pivoting armature, a pivotally mounted insulating disc, contact means carried by said disc, a spring connected to said disc and movable by said armature to cause movement of said contact disc, contact means comprising a pivotally mounted contact, spring means biasing said contact, means limiting the pivotal movement of said contact and permitting said contact to move in the same direction during switch opening as said movable contact means in amount sufllcient to enable said fixed contact spring means to act at the dead center position of said spring to ensure continuous contact movement in switch opening direction as said movable contact means reaches the dead center position.

3. In a relay switch, electro-magnetic .operating means, a. pivotally mounted insulating disc, a contact member mounted thereon, over-center spring means moved by said electro-magnetic operating means and causing said disc to pivot, a second contact member pivotally mounted and spring-biased in the direction of the switch opening movement of said first contact member to impart positive movement to said first contact member at dead center position.

4. In a voltage responsive relay a balanced rotary electro-magnet armature, a disc rotating therewith, a rotary contact moving member comprising a disc, a conductive bridge mounted thereon, a contact member connected to said bridge and mounted on said disc, a second contact engageable by said first contact, pivotal mounting means for said second contact permitting limited movement thereof suflicient to cause positive action of the second contact on the movable contact member at the dead-center position to ensure continuous switch opening movement, spring means connecting said armature disc and contact disc for over-center action to move said contact member in response to armature movement.

5. In a relay switch, electro-responsive operating means, an over-center spring moved thereby, a contact carrying disc pivotally mounted at its center, a first contact member carried by said disc, a second contact member pivotally mounted and engageable by the first contact member, a spring-biasing member separate from said second contact member urging said second contact member in direction of switch opening movement of the first contact member, means to restrict the rotation of the second contact member but permitting it to impart positive movement in circuit opening direction to the first contact member at dead-center position.

6. In a relay switch, electro-magnetic operating means, an over-center spring moved thereby, a pivotally mounted insulating disc operated by said over-center spring, contact means carried by said disc, stationary contact means engageable by said moving contact means, spring means cooperating with said fixed contact and acting at dead-center to impart positive movement to said moving contact, and means to adjust the position of said stationary contact without aflecting said contact spring means to correctly correlate the action of said over-center spring and said contact spring components.

7. In a voltage responsive relay switch, an

overcenter switch mechanism, electromagnetic operating means therefor, fixed and movable contact means, means to alter the position of. the fixed contact means and concomitantly to adjust the position and stress of said overcenter mechanism thereby to cause it to respond to different desired voltage conditions in said electromagnetic means.

8. In a voltage responsive relay switch, electromagnetic operating means, fixed and movable contact means, means for moving said movable contact means, an overcenter spring connecting said operating means and the means for moving said movable contact means, means to alter the position of the fixed contact means and conjointly to adjust the position of said overcenter spring to cause the switch to respond to the desired voltage condition in the electromagnetic means.

9. In an electromagnetic relay switch, a solenoid coil, a rotary armature actuable by said coil and returned to a certain position when unactuated by said coil, stop means to fix said position, means to adjust said armature relative to said stop means to account for variations in coil characteristics, fixed and movable contact means, overcenter mechanism actuated by said armature for moving said movable contact means, means to adjust the position of said overcenter mechanism to cause the switch to respond to the desired voltage conditions in said coil, both aforementioned adjustments being independent whereby the adjustments for coil characteristic variation and the adjustments for voltage conditions may be separately made.

10. An electromagnetic relay switch as claimed in claim 9 wherein the armature is mounted on a threaded spindle for adjustable positioning thereon.

11. An electromagnetic relay switch as claimed in claim 9 wherein the adjustment of the position of the overcenter mechanism is provided by means to adjust the fixed contact means and concomitantly the overcenter mechanism.

12. An electromagnetic relay switch as claimed in claim 9 wherein the armature is mounted on a threaded spindle for adjustable positioning thereon, and the adjustment of the position of the overcenter mechanism is provided by means to adjust the fixed contact position and overcenter mechanism conjointly.

13. In a voltage responsive relay, a rotativelybalanced oscillating electromagnetic armature, a separate rotatively balanced oscillating contact member operated by said armature, a pair oi rotatively balanced contacts separate from said oscillating contact member, one contact of said pair being engaged by said oscillating contact member in one position of the latter and the other of said pair being engaged by said oscillating contact member in another position of the latter, means associated with said pair to alter the position of each independently of the other and of said oscillating contact member.

14. In a voltage responsive relay, a rotativelybalanced o'scillating electromagnetic armature, means to bias and limit oscillatory motion of the armature, a separate rotatively-balanced oscillating contact member, a pair of rotatively-balanced contacts separate from said oscillating contact member, one contact of said pair being engaged by said oscillating contact member in one position of the latter and the other of said pair being engaged by said oscillating contact member inanother position of the latter, means associated with said pair of contacts to bias and limit their motion, additional means associated with said pair to alter the position of each independently of the other and of said oscillating contact member, and spring means forming the sole connection between said armature and said oscillating contact member.

15. In a voltage responsive relay, electromagnetic operating means including a coil and a rotatively-balanced oscillating electromagnetic armature, a separate rotatively-balanced oscillating contact member operated by said armature, adjusting means associated with said armature to account for variations in coil characteristics and difierent desired operating conditions, a pair of rotatively-lbalanced contacts separate from said oscillating contact member, one contact of said pair being engaged by said oscillating contact member in one position of the latter and the other of said pair being engaged by said oscillating contact member in another position of the latter, means associated with said pair of contacts to bias and limit their motion, additional means associated with said pair to alter the position of each independently of the other and of said oscillating contact member.

16. In a voltage responsive relay, electromagnetic operating means including a coil and a rotatively-balanced oscillating electromagnetic armature, a separate rotatively-balanced oscillating contact member operated by said armature, adjusting means comprising a spindle for said armature and means to secure said armature and spindle in difierent angular positions to account for variations in coil characteristics and different desired operating conditions, a pair or assess? rotatively-balanced contacts separate from said oscillating contact member, one contact of said pair being engaged by said oscillating contact member in one position of the latter and the other of said pair being engaged by said oscillating contact member in another position of the latter, means associated with said pair of contacts'to bias and limit their motion, additional means associated with said pair to alter the position of each independently of the other and of said oscillating contact member, and spring means forming the sole connection between said armature and said oscillating contact member.

HAROLD E. scnznirrcmsra REFERENCES CITED The following references are 0! record in the file of this patent:

Number Number 10 UNITED STATES PA'I'ENTS Name Date Goold Jan. 10, 1893 Wood Feb. 12, 1901 Sellner May 7, 1901 Schack Nov. 27, 1917 Wood Feb. 19, 1924 Hardin Jan. 27, 1925 Knight May 13, 1930 Phelan May 24, 1932 Dybvig Apr. 25, 1933 Blosser June 13, 1933 Johnson Sept. 10, 1935 Lamb May 26. 1936 List Oct. 1, 1940 Hansen Feb. 17, 1942 FOREIGN PATENTS Country Date France Aug. 22, 1936 

